Urgent response please

My employer certified me the migrant and dependents for maintenance cost on my COS. I’ve been to Uk for some time and want my dependents to join me, do I still need to get another letter from my employer on maintenance for my dependents or they can use mine on the certificate of sponsorship.
Thanks

The sponsor's certification of maintenance for your dependants applies throughout the validity period of the CoS so you don't need to do anything further about their maintenance.